When Texas coach Mack Brown fired former Longhorn defensive coordinator Manny Diaz, he did more than shake up the UT program and fan base. He made sure every offensive coordinator the Longhorns faced for the remainder of the season would have to throw out what they thought they knew about Texas' defense.

Defensive coordinator Greg Robinson took control of the Texas defense during Week 3 of the season after Texas gave up an eyebrow-raising 550 yards rushing to Brigham Young in a 40-21 defeat.

But after dropping another game to then-No. 25 Mississippi the Longhorns have put together back-to-back wins and showed the subtle changes Robinson has made are working. The Sooners have taken notice.

SCOOPHD: OU STILL WORKING TO FIGURE OUT UT'S NEW DEFENSE

video by Eddie Radosevich

"Obviously, they've changed their defense a little bit since then with the new coordinator," said senior center Gabe Ikard. "We really don't have that much film to go off of with him calling their defense. It makes it a little more difficult for us."

Ikard said it's more important for the offensive linemen to focus on their individual assignments on game day than in past years because of the 2013 look of the Longhorn defense.

If the Sooners can do that and continue to show outstanding ball security it did in the three previous clashes between themselves and the Longhorns, he believes Oklahoma can walk out of the Cotton Bowl with a win on Saturday.

"They've turned the ball over, and we've taken care of the ball," Ikard said. "I don't think it's one of those things where we've significantly done something. Those two lopsided wins the last two years, they didn't take care of the ball as well as we did. That's something that we preach every single day is we have to take care of the football."

Co-offensive coordinator Josh Heupel said the Longhorns have the ability play sound run-defense but aren't nearly as blitz-happy as they've been in the past years.

"Certainly, you're going to pay attention to who he is and what he's done in the past," Heupel said. "In the short amount of time that he's been there, you get a chance to see a little of how he wants to use his personnel. He had a couple extra bigs, so I expect a couple extra wrinkles as well."

DEFENSIVE THEORY

Senior corner back Aaron Colvin hypothesized why the Sooner defense has been one of the best in the country this season.

"I think guys are just playing faster," Colvin said. "I think guys are playing just relentless. I preached onto this defense that we just need to stay consistent and just have that swagger about us.

We're not going to let anybody come in here and run the ball or pass the ball and dominate us as a defense. I feel like guys are doing that. Guys are hungry for it, and it's making a difference."

KNIGHT THROWING ON THE SIDELINES AGAINST TCU

During the third quarter of No. 12 Oklahoma's game against Texas Christian, redshirt freshman quarterback Trevor Knight and redshirt sophomore Kendal Thompson could be seen warming up on the sideline.

Junior quarterback Blake Bell had taken a hard hit earlier but was still the Sooners' signal caller when the game was tight. The Sooners were shutout in that quarter, and TCU had narrowed OU's lead to 13-10 when the fourth quarter began.

Still, Oklahoma coach Bob Stoops said there was never a thought of putting Knight in the game.

"No, we weren't contemplating that," said Stoops at his weekly press conference Monday. "He was just warming up, just in case."

Stoops admitted during the week leading up to the OU-TCU matchup having Knight spell Bell for some plays in the future might not be a bad idea.

PLAYING IN OU-TEXAS HIGHLIGHT OF CAREER

Many Sooners and OU coaches point to an edition of the Red River Rivalry as one of the most memorable games they've played in. Others say it's the reason they chose to attend OU.

Here's what some of them have to say about it this year:

"Whenever you go, I'm sure it's the same way down there, but when you come here that's all players talk about when you're being recruited. You're like 'Yeah, OK.' But it surpasses what they talk about. It's special, a special game."

"There's no game like this one. Walking out of the tunnel at the Cotton Bowl -- if you haven't experienced it it's hard to explain to somebody, especially the freshmen. They don't know what the big deal's all about, but they'll know on Saturday."